IFC_ELEX_Q&A_3
A ratio detector is a circuit for demodulating:
FM
A reactance modulator produces:
FM.
Weather satellites generally send images by:
Facsimile
Of the following, which does not denote a type of capacitor?
Ferrite
The abbreviation FTP stands for:
File Transfer Protocol
A heptode tube has:
Five grids
Which of the following types of mass storage provide the fastest access time?
Flash memory
A common lab multimeter cannot measure:
Frequency.
A communicationc circuit in which either operator can interrupt the other at any time is called:
Full duplex
In a supply designed to provide high power at low voltage, the best rectifier design would probably be:
Full wave, center-tap
Which of the following materials is/are commonly used as a semiconductor?
Gallium arsenide.
In a junction FET, the control electrode is usually the:
Gate
The control grid of a tube corresponds to the:
Gate of an FET
A broadband PA is:
Generally easy to use
As the frequency of ac increases in a coil, the reactance:
Gets larger positively
For a given value of capacitance, as the frequency goes down, the reactance:
Gets more and more negative
An advantage of a grounded-grid power amplifier is:
Good stability
Which of the following is not an advantage of ICs over discrete components?
Greater power capability
An example of a mass-storage device is a:
Hard drive
A tapped coil is used in a(n):
Hartley oscillator
The current consists mainly of holes when a JFET:
Has a P-type channel
An element of matter:
Has a unique number of protons.
A radio-frequency oscillator usually:
Has most or all of its energy at a single frequency
In a multi-cavity klystron, the electrons:
Have variable speed
If the mirror on the face of a multimeter is used properly, where will the image of the pointer appear?
Hidden behind the pointer *
A klystron is noted for its:
High achievable output power
In a parallel-resonant LC circuit, the impedance is:
High and resistive.
The gate of a JFET has:
High impedance
A voltmeter has a high sensitivity when it has which of the following characteristics?
High ratio of internal resistance to full-scale deflection indication *
Meggers (megohmmeters) are used to measure which of the following quantities?
High resistance *
Electrostatic meter movements are used to measure which of the following current/voltage values?
High voltage *
An advantage of parallel data transfer over serial transfer is:
Higher speed.
Because of the small size of ICs compared with equivalent circuits made from discrete components:
Higher switching speeds are attainable
To keep the effect of a voltmeter on a circuit to a minimum, the internal resistance of the voltmeter must have which of the following relationships to the circuit load?
Higher than *
When the current in a conductor is measured without the conductor being disconnected, which of the following meters could be used?
Hook-on voltameter *
Cross-referencing among Web pages can be accomplished by means of:
Hypertext
What is an advantage of digital signal processing (DSP)?
Improved signal-to-noise ratio.
A voltmeter should be connected in an electrical circuit in what manner?
In parallel with the load *
How should an ohmmeter be connected in an electrical circuit?
In parallel with the load *
How are ammeters connected in an electrical circuit?
In series with the load *
An oscillator might fail to start for any of the following reasons except:
In-phase feedback
Which of the following methods is used to dampen a meter?
Incorporate an airtight chamber containing a van *
The high component density of integrated circuits acts to:
Increase the operating speed
Which type of component is generally not practical for fabrication in an IC?
Inductors
The capacitance between two parallel sheets of metal is:
Inversely proportional to the distance between them.
A tube type radio receiver:
Is bulky and heavy
The input impedance of a MOSFET:
Is extremely high
A varactor diode:
Is good for use in frequency synthesizers
The axis of the geomagnetic field:
Is slanted with respect to the rotational axis.
An IMPATT diode:
Is used as a microwave oscillator
How does an ammeter affect the circuit being measured?
It acts as a resistances in series and lowers the circuit current *
One advantage of ac (compared with dc) as a source of utility power is that:
It can be easily stepped up or down in voltage.
If the source-gate junction in an FET conducts:
It is a sign of improper bias
A disadvantage of a MOS component is that:
It is easily damaged by static electricity
An advantage of full-wave bridge rectification is:
It uses the whole transformer secondary for the entire ac input cycle
In a RAM:
It's easy to get data out and put it in
In a ROM:
It's easy to get data out, but hard to put it in
If the load impedance for an oscillator is too high:
It's not a cause for worry; it can't be too high
The main factor that limits the frequency at which a P-N junction will rectify is the:
Junction capacitance.
In an oscillator circuit, the feedback should be:
Just enough to sustain oscillation
Synchronizing pulses in a video signal:
Keep the image from "tearing" or "rolling"*
One way to keep interelectrode capacitance to a minimum is to:
Keep wire leads short.
A utility meter generally measures:
Kilowatt hours
An advantage of a LEO communications satellite system over a geostationary communications satellite is the fact that:
Large, high-gain antennas are not required.
A voltmeter has an effect on the circuit being measured; what is this effect called?
Loading *
If X and Y are both high, what is the state of X NOT Y?
Low
If X is high, what is the state of X NAND Y?
Low
If X is low, what is the state of X AND Y?
Low
An advantage of a crystal-controlled oscillator over a VFO is:
Low drift
An asset of a dot-matrix printer is:
Low operating cost
An advantage of MOSFETs over JFETs is that
MOSFETs can handle a wider range of gate voltages
The d'Arsonval meter movement is based on which of the following principles?
Magnet moving-coil
Which of the following is a serial-access medium?
Magnetic tape
The "brain" of a computer is the:
Microprocessor
What area of an ohmmeter scale should be used when a measurement is taken?
Mid-scale portion *
An audio oscillator that uses two amplifiers in cascade, with positive feedback from the output of the second stage to the input of the first stage, is known as a:
Multivibrator.
Which of the following is not characteristic of an oscillator?
Negative feedback
When, if ever, can you use a dc ammeter to measure ac values?
Never *
Which of the following safety precautions does NOT apply to a multimeter?
Never apply power to the circuit when measuring voltage with the meter *
A ferromagnetic-core coil is preferred for use in the tuned circuit of an RF oscillator:
No! Air-core coils work better in RF oscillators
Frequency multiplication is possible with a semiconductor diode because the diode is:
Nonlinear.
A diode can be used as a frequency multiplier because of its:
Nonlinearity
A reason CDs don't wear out with repeated playback is:
Nothing touches the disk
Resistivity of wire can be specified in:
Ohms per meter.
In an AND gate, the output is high
Only when all inputs are high
In an exclusive OR gate, the output is high:
Only when the inputs have opposite logic states
A Colpitts circuit is a form of:
Oscillator
Voltage regulation can be accomplished by a Zener diode connected in:
Parallel with the filter output, reverse-biased
A platter is a:
Part of a hard dive
The World Wide Web is:
Part of the Internet
An RF choke:
Passes dc but not RF
A tube with three grids is called a:
Pentode
When the bias in an FET stops the flow of current, the condition is called:
Pinchoff
The oscillating frequency of a quartz crystal can be varied slightly by:
Placing a small variable capacitor across the crystal
The principal disadvantage of a voltage multiplier is:
Poor regulation
In a power supply, resistors are sometimes connected in series with the diodes in order to:
Protect the diodes against surge currents
A resistor between the base of an NPN bipolar transistor and the positive supply voltage is used to:
Provide proper bias
A loading control in a tuned PA:
Provides an impedance match between the bipolar transistor or FET and the load
In a magnetron, as the frequency is increased:
The achievable power output decreases
In a cathode-ray tube (CRT), the term electrostatic deflection means that:
The beam is bent by an electric field
In an enhancement-mode MOSFET:
The channel does not conduct with zero gate bias
In a parallel combination of light bulbs, if one bulb socket totally shorts out:
The circuit had better have a fuse or a circuit breaker.
In a PNP bipolar transistor:
The collector is negative relative to the emitter
The logical statement X + Y = Y + X depicts:
The commutative property.
When several resistances are connected in series:
The current is the same through each one
In an NPN bipolar transistor circuit:
The dc collector voltage is positive.
When an enhancement-mode MOSFET is at zero bias:
The drain current is zero with no signal
In a P-channel JFET:
The drain is negative relative to the source
In a common-emitter bipolar-transistor circuit:
The emitter is at signal ground.
In a tube with a directly heated cathode:
The filament serves as the cathode
The part of a power supply immediately preceding the regulator is:
The filter
A current surge takes place when a power supply is first turned on, because:
The filter capacitor(s) must be initially charged
If a fuse blows, and it is replaced with one having a lower current rating, there's a good chance that:
The fuse will blow out right away
In a source follower, which of the electrodes of the FET receives the input signal?
The gate
The intensity of the electron flow in a vacuum tube depends on all of the following except:
The gate voltage
What voltmeter range should be used for initial measurements?
The highest *
What range of an ammeter should you use for an initial measurement?
The highest range *
A gain of -15 dB in a circuit means that:
The input signal is stronger than the output
Current through a meter results in the pointer. In d'Arsonval meter movement, what force produces this deflection?
The interaction of magnetic fields
The paths of the electrons in a magnetron are spirals, rather than straight lines, because of:
The longitudinal magnetic flux
The ammeter with the greatest sensitivity has which of the following characteristics?
The lowest amount of current for full-scale deflection indication *
The data in a volatile computer memory:
Vanishes if power is removed
A diode that can be used as a variable capacitance is a:
Varactor.
In a time-domain oscilloscope, the waveform to be analyzed is usually applied to the:
Vertical deflection plates or coils
The henry is a:
Very large unit.
In an N-channel JFET, pinchoff occurs when the gate bias is:
Very negative
Compact disks (CDs) are not generally for recording:
Via magnetic fields
The electrostatic meter movement reacts to which of the following electrical properties?
Voltage *
What electrical property is measured by a voltmeter?
Voltage *
A multimeter can be used to measure which of the following electrical properties?
Voltage, Current, Resistance
Electrostatic forces can be measured to directly indicate:
Voltage.
Another name for joules per second is:
Watts
Wave X leads wave Y by 270 degrees. This would be better expressed by saying that:
Wave X lags wave Y by 90 degrees.
A piano sounds different than a saxophone, even if the notes are at the same frequency, because of a difference in:
Waveform.
When a JFET is pinched off:
dID/dEG is zero with no signal
The forward base bias in a transistor is
increased until the collector current levels off.
In many cases, a PNP transistor can be replaced with an NPN device and the circuit will do the same thing, provided that:
- The supply polarity is reversed
A bipolar transistor has:
- Three semiconductor layers
In a certain resistance-capacitance (RC) circuit, the current leads the voltage by 45 degrees. The resistance is 50 ohms. The capacitive reactance is:
-50 ohms.
Which of the following voltages might normally represent a 1 in negative logic?
0 V
A typical audio recording tape thickness is:
1 mil
Three resistors, each of 30 ohms, are connected in parallel. The net resistance is:
10 ohms.
Three resistances are in parallel, with values of 100, 200, and 300 ohms. The current through the 200-ohm resistor is 500 mA. What is the voltage across the whole combination?
100 V.
The value of the decimal number 23 in binary form is:
10111
One megabyte is the same amount of data as:
1024 K
A resistor has a positive temperature coefficient of 1.00 percent per degree C. If its value is 100 ohms at 20 degrees C, what is its value at 25 degrees C?
105 ohms.
A resistor of 100 ohms carries 333 mA dc. The power dissipated by that resistor is:
11.1 W
A transformer has a primary-to-secondary turns ratio of 10:1. The input is 120 V rms ac. The output is:
12 Vrms ac.
The output of a circuit is 20 V and the input is 5.0 V. This is a gain of:
12 dB.
In three-phase ac, the difference in phase between any two waves is:
120 degrees.
A circuit has a complex impedance of 9 + j12. The absolute-value impedance is:
15 ohms.
A logic circuit has four inputs W, X, Y, and Z. How many possible input combinations are there?
16
The fifth digit from the right in a binary number carries a decimal value of:
16
In a rectifier diode, current flows for approximately how much of the ac cycle
180 degrees
A transformer quadruples the ac voltage. The primary-to-secondary impedance ratio is therefore:
1:16.
An amplifier has a dc collector power input of 300 W, and is 75.0 percent efficient. The signal output power is:
225 W
A power gain of 44 dB is equivalent to an output/input power ratio of:
25,000
A circuit has a battery of 3.0 V and a bulb with a resistance of 12.0 ohms. The current through the bulb is:
250 mA
If a circuit has a voltage-amplification factor of 20, then voltage gain is:
26 dB
A transformer secondary provides 10 V rms to a voltage-doubler circuit. The dc output voltage is about:
28 V
The Web would probably work fastest for a user in New York at:
2:00 A.M local time on a Tuesday
An amplifier has an output signal voltage that is 35 times the input signal voltage. This is a gain of:
31 dB
The gain of a transistor in a common-emitter circuit is 100 at a frequency of 1000 Hz. The gain is 70.7 at 335 kHz. The gain drops to 1 at 210 MHz. The alpha cutoff is:
335 kHz
A class-A amplifier conducts during how much of the input cycle?
360 degrees.
A device has a voltage gain of 23 dB. The input voltage is 3.3 V. the output voltage is:
47 V
The binary number 110001 represents the digital number
49
A certain bipolar-transistor PA is 66 percent efficient. The output power is 33 W. The dc collector power input is:
50 W
If a half-wave rectifier is used with 117-V rms ac (house mains), the average dc output voltage is about:
52.7 V
The largest possible decimal number that can be represented by six binary digits (bits) is:
63
In a 360-Hz wave, degree of phase represents:
7.72 microseconds
If a full-wave bridge circuit is used with a transformer whose secondary provides 50 V rms, the PIV across the diodes is about:
70 V
Two 400-μH inductors are connected in series. There is no mutual inductance. The total inductance is:
800 μH
AN example of a device that commonly oscillates is:
A Gunn diode
A form of microwave electron tube is:
A Klystron.
A logic circuit has an output 0 when the input is 1, and vice versa. This is:
A NOT gate
A component that discharges filter capacitors after a power supply has been switched off is called:
A bleeder resistor
An enhancement-mode MOSFET can be recognized in schematic diagrams by:
A broken vertical line inside the circle
Which of the following would make the best filter for a power supply?
A capacitor in parallel and a choke in series
A simple power supply filter can be built with:
A capacitor in parallel with the dc output
A simple power supply filter can be made using:
A capacitor in parallel with the rectifier output.
Trans conductance is the ratio of:
A change in drain current to a change in gate voltage
The VA power is equal to the true power only when:
A circuit has no reactance.
How can a class-C amplifier be made linear?
A class-C amplifier cannot be made linear
If a multimeter has no OFF position, and it is returned to storage, on which of the following positions should the meter be set?
Ac; highest voltage range *
A tuned PA must always be:
Adjusted for maximum power output
Ferromagnaetic coil cores are not generally good for use in RF oscillators because:
Air-core coils have better thermal stability
The channel in a zero-biased JFET is normally:
All the way open
If X = 0 and Y = 1, then x(Y + Z) is:
Always 0
If X = 1 and Y = 1, then X + YZ is:
Always 1
Which of the following safety precautions should be observed when an ohmmeter is used?
Always start with the highest scale of the meter; Deenergize the circuit before connecting the meter; Observe proper polarity
Types of meters can be made from a current sensitive meter movement?
Ammeter, Ohmmeter, Voltmeter
A modem contains:
An A/D converter
An optoisolator consists of
An LED and a photodiode
The electron beam in an electrostatic CRT is bent by:
An electric field
If you place a bar of iron inside a cylindrical coil of wire, and then run dc through the wire, you have:
An electromagnet.
A small 9-V battery might be used to provide power to:
An electronic calculator
Which type of component is impractical to fabricate on a silicon chip?
An inductor
One of the main shortcomings of MOSFETs is that they:
Are easily damaged by static electricity.
Magnetic lines of flux are generally:
At right angles to the flow of current.
When computer data is sent over long-distance telephone circuits, the digital highs and lows are generally represented by:
Audio tone
When a semiconductor is reverse-biased with a large enough voltage, it will conduct. This is because of:
Avalanche effect
A d'Arsonval meter movement reacts to which of the following values of voltage?
Average *
Which of the following safety precautions should be observed when a megger is used?
Do not touch the meter leads when a measurement is being taken *
Image resolution can be specified in terms of:
Dot pitch
Characteristic curves for JFETs generally show:
Drain current as a function of drain voltage
Which of the following IC types must be physically removed from the circuit to have its memory contents changed?
EPROM
Admittance is a quantity expressing:
Ease with which a circuit passes ac.
What value of ac is indicated by a meter scale?
Effective *
The rms value for an ac wave is also sometimes called the:
Effective value.
Which of the following meter movements will measure either ac or dc without the use of a rectifier?
Electrodynamic *
A complementary-metal-oxide-semiconductor (CMOS) IC:
Employs N-channel and P-channel FETs on a single chip.
The electron volt is a unit of:
Energy.
A frequency synthesizer has:
Exceptional stability
In a video recording tape, the image signal tracks are:
Diagonal with respect to the edges of the tape
The different sounds of musical instruments are primarily the result of:
Differences in the waveshape
Transient suppression minimizes the chance of:
Diode failure
An advantage of magnetic disks over magnetic tape is:
Disks allow faster data storage and retrieval
The current through the channel of a JFET is directly affected by all of the following except:
Transconductance
A disadvantage of transformer coupling, as opposed to capacitive coupling, is that:
Transformers cost more
Which type of digital IC is least susceptible to noise?
Transistor-transistor logic
One difference between a triode and an N-Channel FET is that:
Triodes need more voltage
If you needed exceptionally good ripple filtering for a power supply, the best approach would be to:
Use two capacitor/choke sections one after the other
Antenna efficiency is:
Usually more important in transmitting systems than in receiving systems.
Which of the following is not an advantage of CMOS?
Ability to handle high power levels
A kilobyte is:
About 1,000 bytes
The beta of a bipolar transistor is the:
Current amplification factor
In a pure inductance:
Current lags voltage by 90 degrees
In a resistance/inductance (RL) series circuit:
Current lags voltage by less than 90 degrees.
An ammeter measures:
Current.
Which of the following voltage could normally represent a 1 in positive logic?
+4 V
The greatest possible amplification is obtained in:
- A common-emitter circuit
The configuration noted for its stability in tadio-frequency power amplifiers is the:
- Common-base circuit
Bleeder resistors are:
- Connected in parallel with filter capacitors
In the dual-diode model of an NPN transistor, the emitter corresponds to:
- Either of the diode cathodes
When a transistor is conducting as much as it possibly can, it is said to be:
- In saturation
In a PNP circuit, the collector:
- Is negative with respect to the emitter
To service a power supply with which you are not completely familiar, you should:
- Leave it alone and have a professional work on it
The current through a transistor depends on:
- More than one of the above
The output is in phase with the input in a:
- More than one of the above
With no signal input, a bipolar transistor would have the least IC when:
- The E-B junction is reverse-biased
The configuration most often used for matching a high input impedance to a low output impedance puts signal ground at:
- The collector
In a common-emitter circuit, the gain bandwidth product is:
- The frequency at which the gain is 1
A cluster is a unit of:
Data on a hard drive
Bits per second (bps) is a unit of:
Data speed
The gigabyte is a unit commonly used as a measure of:
Data storage capacity.
ASCII is a form of:
Data transmission code
A screen grid enhances tube operation by:
Decreasing the grid-to-plate capacitance
Which of the following safety precautions should be observed when a voltmeter is used?
Deenergize the circuit before connecting the meter *
In a wireless system, noise always:
Degrades performance
The rate of change in a quantity is called the:
Derivative.
A beat-frequency oscillator is useful for:
Detecting CW
The function switch on a multimeter does NOT perform which of the following functions?
Determination of the proper scale*
The bipolar transistors or JFETs in a multivibrator are usually connected in:
A common-emitter or common-source arrangement
Which type of IC is used to determine whether voltage levels are the same or not?
A comparator
Which of the following devices always uses an IC as one of its main active components?
A digital computer
A frequency synthesizer makes use of:
A divider
A JFET circuit essentially never has:
A forward-biased P-N junction
Which type of tube maintains constant voltage drop with changes in current?
A gas-filled regulator
A platter is a part of a device known as:
A hard drive
A vacuum tube might be found in:
A high-power radio-frequency linear amplifier
An example of a device that converts electrical energy into visible radiant energy is:
A light-emitting diode.
A type of electron tube useful for generating microwave energy is:
A magnetron
A motherboard contains:
A microprocessor
A channel carries several signals at once. Which type of IC might be used to select one of the signals for reception?
A multiplexer/demultiplexer
For animated graphics involving fast motion, you should ideally use:
A noninterlaced monitor
A device that converts visible light into dc is:
A photovoltaic cell
A packet is:
A piece of a file sent over the Net
A device that converts ultrasound into electrical signals by taking advantage of the properties of a crystalline or ceramic substance is:
A piezoelectric transducer
A JFET is sometimes biased at or beyond pinchoff in:
A power amplifier
A Zener diode would most likely be used in:
A power supply regulating circuit
The most stable type of oscillator circuit uses:
A quartz crystal
A fuse with a nothing but a straight wire inside is probably:
A quick-break type
In which of the following devices would you be least likely to find an integrated circuit as the main component?
A radio broadcast transmitter's final amplifier
A JFET might work better than a bipolar transistor in:
A radio receiver
A common-base circuit is commonly employed as:
A radio-frequency power amplifier
A type of FM detector that has its limiter built in is:
A ratio detector.
What device allows a d'Arsonval meter movement to measure ac by converting ac to pulsating dc?
A rectifier *
Which of the following configurations extends the range of a voltmeter?
A resistor in series with the meter movement *
A cell that can be recharged, and therefore used again and again, is called:
A secondary cell.
A Colpitts oscillator can be recognized by:
A split capacitance in the tuned circuit
Oscillation requires:
A stage with gain
A class-A circuit would not work well as:
A television transmitter PA
A very brief high-voltage spike on an ac power line is called:
A transient
The schematic symbol for an op amp is:
A triangle
Boolean algebra is:
A useful tool in digital logic circuit design
A voltage-controlled oscillator makes use of:
A varactor diode
As the frequency of an alternating current decreases toward zero (dc), the reactance of a capacitor:
Becomes large negatively.
How is the effect that an ammeter produces in a circuit kept to a minimum?
By ensuring that the meter resistance is low compared to circuit resistance *
How can a class-B amplifier be made suitable for hi-fi audio applications?
By using two transistors in push-pull
When both N and P type semiconductors are found in an IC, the technology is known as:
CMOS
A good type of resistor to use in a radio amplifier is:
Carbon composition
The electron gun in a CRT is another name for its:
Cathode
The current-carrying part of a field-effect transistor, analogous to a garden hose in some ways, is called the:
Channel
A voltage-doubler power supply is best for use in:
Circuits that need low current at high voltage
Which type of amplifier circuit provides the greatest efficiency?
Class C
Which of the following amplifier types produces the least distortion of the signal waveform?
Class-A
Which bipolar amplifier type has some distortion in the signal wave, with collector current during most, but not all, of the cycle?
Class-AB2
In which of the following FET amplifier types does drain current flow for 50 percent of the signal cycle?
Class-B
Which of the following amplifier classes generally needs the most driving power?
Class-B
Which type of amplifier circuit has the transistor or FET biased exactly at cutoff or pinchoff when there is no signal input?
Class-B.
In a common-base circuit, the output is taken from the:
Collector
The output electrode of a bipolar transistor is usually the:
Collector
Which of the following bipolar-transistor circuits can provide the most amplification?
Common emitter
Which of the following circuits generally has the greatest gain?
Common source
Which of the following circuits has its output 180 degrees out of phase with its input?
Common source
Elements can join together to form:
Compounds.
Image resolution is an important specification in:
Computer monitors
Protocol ensures that:
Computers can exchange data
In an AM voice signal, the audio information is:
Contained in sidebands
An ohmmeter is used to check for which of the following conditions?
Continuity *
In a radio-frequency power amplifier using a vacuum tube, stability is enhanced by grounding the:
Control grid
An op amp usually employs negative feedback to:
Control the gain
What electrical property is measured by an ammeter?
Current *
What electrical property is reacted to by the electrodynamic, d'Arsonval, moving vane, and thermocouple meter movements?
Current *
A memory that can be easily accessed, but not written over, is called
ROM.
An ohmmeter can measure different ranges because of the use of which of the following components?
Range resistors *
The input signal to a transistor amplifier results in saturation during part of the cycle. This produces:
Reduced efficiency
Negative feedback in an amplifier:
Reduces the gain
The decibel is a unit of:
Relative signal strength
What electrical property is measured with an ohmmeter?
Resistance
Inductances in parallel, assuming there is no mutual inductance, add up like:
Resistances in parallel.
A dc voltage-divider network is made using:
Resistors.
Which type of modulation consists of one voice sideband, with a suppressed carrier?
SSB
This condition is:
Saturation.
A vidicon camera tube is noted for its:
Sensitivity
Signal-plus-noise-to-noise ratio (S + N / N) is often specified when starting a receiver's:
Sensitivity
One of the problems encountered in building a multimeter is that the meter movement gives different readings for the same values of ac and dc. Which of the following features of a multimeter will solve this problem?
Separate scales for ac and dc *
Data sent along a single line, one bit after another, is called:
Serial
Ohmmeters are classified by type. What are the two types of ohmmeters?
Series and shunt *
Acoustic feedback in a public-address system:
Serves no useful purpose
The inputs of an R-S flip-flop are known as:
Set and reset
Ammeters measure various ranges through the addition of which of the following components?
Shunt resistors in parallel with the meter movement *
The ac in the utility mains is usually:
Sinusoidal
What is meant by the term "meter damping"?
Smoothing the oscillations of the pointer *
A thermal printer might be the best of printer for:
Someone who travels a lot
The extent to which an oscillator maintains a constant frequency is called its:
Stability
An advantage of a laser printer over a dot-matrix printer for computer applications is:
Superior image quality
The reciprocal of the reactance is called:
Susceptance
Safety precautions should be observed prior to connecting an ammeter into a circuit.
Switch to the highest range. Observe proper dc polarity. Deenergize the circuit
Which layer of the ionosphere absorbs radio signals below about 7 MHz during the daylight hours?
The D layer
Which of the following is an example of wireless technology?
The Global Positioning System
High voltages are better than low voltages for long-distance electric power transmission because:
The I2R losses are lower
An advantage of a J-K over an R-S flip-flop is that:
The J-K always has predictable outputs
In a P-channel JFET:
The majority carriers are holes.
What portion of the ammeter scale should be used to take a final reading?
The mid-scale portion *
A disadvantage of a half-wave rectifier is the fact that:
The output is hard to filter
When both inputs of R-S flip-flop are 0:
The outputs stay as they are
In positive-edge triggering, the change of state occurs when:
The pulse level is going from low to high
If an ac impedance is a pure resistance, then:
The reactance is zero
When both inputs of an R-S flip-flop are 1:
The resulting outputs can be absurd
What is the most obvious differences in the two types of ohmmeters?
The scales of the meters *
In a step-up power transformer:
The secondary voltage is more than the primary voltage
The capacitance values in an amplifier circuit depend on:
The signal frequency
An absolute limit on IS component density is:
The size of the semiconductor atoms
The frequency at which a crystal oscillator functions is determined mainly by:
The thickness of the crystal
In magnetic audio tape:
The tracks are parallel to the edges
In magnetic video tape:
The video tracks are diagonal
In a reverse-biased semiconductor diode, the capacitance depends on:
The width of the depletion region
In a tube with a cold cathode:
There is no filament
Out-of-circuit meters have which of the following advantages over in circuit meters?
They can be used on more than one device
The hairsprings in a d'Arsonval meter movement perform which of the following functions?
They make electrical connections to the meter movement
If X is high and Y is low, what is the state of X NOT Y?
This logic statement makes no sense
The horizontal displacement on an oscilloscope CRT screen is usually measured in:
Time per unit division
Why is there a mirror on the face of a multimeter?
To aid in reducing parallax error *
Circuit measurement is used for what purpose?
To determine the reason a circuit is not functioning properly
An in-circuit meter is used for what purpose?
To monitor circuit operation
A graphic equalizer is a form of:
Tone control
In a purely resistive impedance, there is:
Zero reactance
The ripple frequency from a full-wave rectifier is:
twice that from a half-wave circuit
When a megger is used to check the insulation of a wire, which of the following indications should be considered normal?
∞ *
